The present invention relates to a semiconductor integrated circuit, a variable gain amplifier, and a sensing system. For example, the present invention relates to a semiconductor integrated circuit that is suitable for configuring a high-accuracy variable gain amplifier, a variable gain amplifier, and a sensing system.
In recent years, a high-accuracy variable gain amplifier has been demanded. A related technique is disclosed in Japanese Unexamined Patent Application Publication No. 2003-8375.
A variable gain amplifier disclosed in Japanese Unexamined Patent Application Publication No. 2003-8375 is provided with a gm cell that generates and outputs an output current corresponding to an input signal voltage and a current voltage conversion circuit that converts the output current of the gm cell to a voltage and includes an adjustment means for adjusting a conversion gain. The current voltage conversion circuit includes an operation amplifier and a variable resistor that is connected between an input terminal and an output terminal of the operation amplifier and is capable of setting any resistance value.